There are currently four user preferences for Muting another user:
* Local Email mute
* Local Notifications mute
* Global Email mute
* Global Notifications mute
This bifurcated (quadfurcated?) situation places a cognitive burden on our users, many of whom don't understand the concept of local-vs-global relationship in the first place. While cross-wiki harassment is not common, we owe it to our users to protect them and to have our "Mute" features performs as expected — to prevent unsolicited communications from known parties.
There are a few things that can be explored for these preferences:
* {T167902} would provide some value but it would be a somewhat expensive venture.
* Add help text to the local preferences to point people to global preferences (caution: this is just //more// cognitive load.)
* Display the global preference on the local preference page.
* Only allow global preferences for these mute lists, and display help text on the local preferences to point people to global preferences.
You'll also need to consider:
* Migrating the lists
* How new, contextual entry points (e.g. email footer, in-notification) store the preference: locally vs. globally
{T216185} should also illuminate any decision made here.